If your computer printer says the printer is offline? Then it means, your operating system doesn't have a connection via your router or other wi-fi connection. Actually, WI-FI connection is a bridge or you can say a bypass that keeps your printer in a live mood but as you lose your connection. It automatically says in the notification into your operating system that your printer is offline. And since the device driver is not connected via your operating system, you can't access between printer and monitor. So, first of all, you have to check out there that you properly connected your printer to the electricity board and to the monitor.